I recently tried to change my login screen wallpaper with some terminal command that I read somewhere, but it didn't work and now my login screen is "default" blue. I've tried changing it through various tweaks with no effect. The thread here is the exact same thing: http://discussions.apple.com/thread.jspa?threadID=1207134&tstart=0 The person claims he fixed it, but I don't know how he did it. I see no com.apple.loginwindow in my system/prefernces folder. Is this something you have to trash through terminal? If so, how?